American Civil War was a military conflict between the United States of America (the Union) and the Confederate States of America (the Confederacy) from 1861 to 1865.
The American Civil War is sometimes called the War Between the States, the War of Rebellion, or the War for Southern Independence. It began on April 12, 1861, when Confederate General P. G. T. Beauregard opened fire on Fort Sumter in Charleston Harbor, South Carolina, and lasted until May 26, 1865, when the last Confederate army surrendered. The war took more than 600,000 lives, destroyed property valued at $5 billion, brought freedom to 4 million black slaves, and opened wounds that have not yet completely healed more than 125 years later.
The chief and immediate cause of the war was slavery. Southern states, including the 11 states that formed the Confederacy, depended on slavery to support their economy. Southerners used slave labor to produce crops, especially cotton. Although slavery was illegal in the Northern states, only a small proportion of Northerners actively opposed it. The main debate between the North and the South on the eve of the war was whether slavery should be permitted in the Western territories recently acquired during the Mexican War (1846-1848), including New Mexico, part of California, and Utah. Opponents of slavery were concerned about its expansion, in part because they did not want to compete against slave labor.